Method and machine for producing a continuous filter rod

ABSTRACT

A method and machine produces a continuous filter rod. At least one type of finite, essentially completely separated fibers is transported with transport air to a conveyor. A fiber nonwoven is formed on one surface of the conveyor to result in the fibers at least partially contacting one another. The fiber nonwoven is deposited onto a wrapping material web. The fiber nonwoven is then wrapped a material web.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the priority of European PatentApplication with Serial No. 03 007 675.6, filed on Apr. 3, 2003, thedisclosure of which, together with the disclosure of each and every U.S.and foreign patent and patent application mentioned below areincorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] The invention relates to a method and a machine for producing acontinuous filter rod.

[0003] A method for processing filter material and the correspondingfilter material processing machinery used in the tobacco industry areknown from British Patent Document GB 718 332, in which materialsnippets are produced with a tobacco cutter and are then fed to acontinuous rod machine in a manner similar to that in cigarettemachines. The snippets are impregnated with a chemical agent to preventan undesirable taste and to prevent the snippets from falling out of theend pieces of the subsequently produced filters The snippets areconveyed with a roller to the operating region of a spiked feed rollerand are then moved by the spiked feed roller to a conveying belt, sothat the snippets can subsequently be fed to a second spiked roller. Thesnippets are knocked from the second spiked feed roller by a furtherspiked or beater roller and supplied to a format device where thecontinuous filter rod is formed by wrapping material around the fiberrod. The snippets consist of materials such as paper, cellulose,textile, synthetic materials and the like and have a texture that issimilar to cut tobacco.

[0004] The shape of the snippets makes it very difficult to producefilters with homogeneous characteristics. In addition, the options ofadjusting the filter characteristics are very limited.

BRIEF SUMMARY OF THE INVENTION

[0005] In contrast to the above-mentioned prior art, it is an object ofthe present invention to develop a method and a machine for producingcontinuous filter rods with homogeneous filter characteristics.

[0006] This and other objects are solved according to the invention bythe provision of a method for producing continuous filter rods. At leastone type of finite, essentially completely separated fibers istransported with transport air to a conveyor. A fiber nonwoven is formedon one surface of the conveyor to result in the fibers at leastpartially contacting one another. The fiber nonwoven is deposited ontoand wrapped with a wrapping material web.

[0007] A continuous filter rod with very homogeneous filtercharacteristics is obtained when essentially completely separated fibersare transported, in particular with transport air, in the direction of aconveyor, such that a fiber nonwoven forms on a conveyor surface. In theexemplary embodiment, the conveyor is a belt conveyor, and can beprovided with a suction belt.

[0008] A uniform shape of the continuous filter rod can be achieved ifthe fiber nonwoven is compacted while being wrapped with the wrappingmaterial web. Supplying energy to the fiber nonwoven during wrappinggenerates a solid bond at the fiber contacting points to result in arelatively elastic filter and ensures that no fiber material is lost atthe cutting edges of the filter and/or the filter element.

[0009] Particularly homogeneous filter characteristics can be obtainedby using fibers having a fiber length that is shorter than the length ofthe filter and/or filter element cut from the produced continuous filterrod. In the exemplary embodiment, the fibers utilized have an averagefiber diameter in the range of 10 to 40 μm, and can be in the range of20 to 38 μm. Thus, in an exemplary embodiment, the fibers are elongatedand relatively thin. The filter characteristics can be adjusted ifadditives such as activated carbon granulate, triacetin or latex areadded to the fibers. Activated carbon granulate is added, for example,to the fibers before they are completely separated or is added to thefibers being transported to the conveyor. Triacetin and/or latex asbonding agents are added, for example, to the compiled fiber nonwoven inthe conveyor region.

[0010] A particularly uniform compaction is ensured if the fibernonwoven is compacted prior to the step of deposition on the wrappingmaterial web. For this, the material is compacted vertically as well ashorizontally, i.e., from the top and from the bottom as well as from thesides of the fiber nonwoven.

[0011] A particularly simple process sequence is ensured if the fibernonwoven is removed from the conveyor with mechanical force, inparticular with compressed air, to deposit the fiber nonwoven on thewrapping material web.

[0012] In one exemplary embodiment, the fiber nonwoven is formed priorto being deposited on the wrapping material web. This forming step, forexample, can include at least the forming of a semicircle crosswise tothe conveying direction of the nonwoven, or a full circle or oval can beformed.

[0013] A filter or a filter element is produced according to theinvention by subsequently cutting the continuous filter rod intosections of a specific length.

[0014] The present invention also includes a machine for producing acontinuous filter rod. The machine includes a fiber compiling devicethat transports separated fiber materials with transport air to aconveyor to form a fiber nonwoven. A format device wraps a material webaround the fiber nonwoven. A transferring device then transfers thefiber nonwoven from the conveyor to the format device.

[0015] A particularly homogeneous fiber nonwoven can be produced bytransporting the separated filter materials with transport air, suchthat an especially homogeneous continuous filter rod can be produced, toresult in particularly homogeneous filter and/or filter elements.

[0016] The filter characteristics can be positively influenced if atleast one compacting device is provided in the area of the conveyor. Inthe exemplary embodiment, the conveyor or a section of the conveyor canform a component of the compacting device. The conveyor can be at leastone suction belt. If the processed fibers are small enough so that theopenings of the suction belt are quickly clogged, it is advantageous iftwo additional suction belts are used for the operation, which arerespectively arranged at an approximately right angle on both sides ofthe first suction belt. The fiber nonwoven can be transferred withparticular efficiency if compressed air is used to remove the nonwovenfrom the conveyor.

[0017] If the device for transferring the fiber nonwoven comprises atransport belt, then the fiber nonwoven can be shaped to meet thecharacteristics and/or the form of the filter to be produced. In theexemplary embodiment, the transport belt is a suction belt, and thetransport belt can be bent crosswise to the transporting direction, thusmaking it easy to produce, for example, a continuous filter rod withcircular and/or oval cross section. Two transport belts can be providedto hold and transport the fiber nonwoven in between to form the circularand/or oval cross section. The transport belts can be designed such thatthe fiber nonwoven is formed into an oval shape, a circular shape, asemi-circular shape, or a half-oval shape.

[0018] An alternative transfer device for transferring the fibernonwoven includes a nozzle through which the fiber nonwoven can betransported. In the exemplary embodiment, the nozzle is designed suchthat the fiber nonwoven can assume a round or oval shape.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The invention is described in the following with the aid ofexemplary embodiments and without restricting the general inventive ideaby referring to the drawings, to which reference is made for all detailsof the invention not explicity explained in the text.

[0020]FIG. 1 shows a three-dimensional schematic representation of aseparating device and a section of a compiling device in accordance withthe present invention.

[0021]FIG. 2 shows a schematic view of a first exemplary embodiment of acontinuous filter rod machine in accordance with the present invention.

[0022]FIG. 3 shows a plan view of a section of the continuous filter rodmachine of FIG. 2, as viewed in the direction of arrow A.

[0023]FIG. 4 shows a side view of a section of the continuous filter rodmachine of FIG. 2, as viewed in the direction of arrow B.

[0024]FIG. 5 shows a schematic view of a second exemplary embodiment ofa continuous filter rod machine in accordance with the presentinvention.

[0025]FIG. 6 shows a plan view of a section of the continuous filter rodmachine of FIG. 5, as viewed in the direction of arrow A.

[0026]FIG. 7 shows a side view of a section of the continuous filter rodmachine of FIG. 5, as viewed in the direction of arrow B.

[0027]FIG. 8 shows a side schematic view of a section of the continuousfilter rod machine of FIG. 2, with portions the machine omitted forreasons of clarity.

[0028]FIG. 9 shows a top schematic view of the section of the continuousfilter rod machine shown in FIG. 8.

[0029]FIG. 10 shows a schematic three-dimensional section of thecontinuous filter rod machine shown in FIG. 2.

[0030]FIG. 11 shows a schematic view of a section of a continuous filterrod machine shown in FIG. 8.,

[0031]FIG. 12 shows a schematic view of a section of a continuous filterrod machine shown in FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION

[0032] In the Figures described herein, the same reference numbers areused for identical or similar elements and/or parts, so that these donot need to be introduced again.

[0033] Referring to FIG. 1, there is shown a three-dimensionalrepresentation of a separating device 10 is a variant of a separatingdevice disclosed in an European Patent Application No. 03007672.3 by theassignee of the present application and entitled “VERFAHREN ZURAUFBEREITUNG ENDLICHER FASERN UND AUFBEREITUNGSEINRIGHTUNG FUER ENDLICHEFASERN ZUR VERWENDUNG BEI DER HERSTELLUNG VON FILTERN” [“Method forProcessing Finite Fibers and Processing Device for Finite Fibers Usedfor the Production of Filters,”] filed on Aug. 8, 2003 in the EuropeanPatent Office. The above-mentioned European Patent Application isdirected to the respective processing of fiber material used for theproduction of filters to obtain essentially completely separated fibersfor producing a homogeneous continuous filter rod. The separating device10, among others, can be used for this purpose. If necessary, the filtermaterial and/or the fiber material is separated and portioned out aheadof time.

[0034] The mostly non-separated fiber material and/or fiber/fiber groupmixture 49, as shown in the schematic representation of FIG. 4, is movedvia an accumulation chute 44 and feed rollers 46 to the operating rangeof a spiked feed roller 76, which knocks out and pre-separates thefiber/fiber group mixture 49. This fiber/fiber group mixture 49 is thentransported with air flow 19 to a screening drum 21, as shown in FIG. 1,via openings 20 on the side of a housing 22. In FIG. 1, two screeningdrums 21 are shown. The fiber material is blown into the housing 22 inthe direction of the longitudinal axes of the screening drums 21. Acircular flow 23 is generated when the fiber material is blown in fromboth sides of the screening drums 21 in counter-clockwise direction inthis exemplary embodiment. Below the screening drums is a fluidized bedregion 11. (See FIG. 1) The circular flow 23 through the screening drums21 is superimposed by a normal flow and/or a flow that is essentiallyperpendicular to the circular flow 23 and is generated by a low pressureat the end 14 of the fluidized bed region 11 that results in air flow13. The air flow 13 represents one option for larger, heavier fibers,which is not always required. The low pressure existing at the end 14 ofthe fluidized bed region 11 is generated by the low pressure of asuction-belt conveyor (not shown in FIG. 1), as well as by an air flow17 through an exhaust pipe 16. (See FIG. 1) The normal flow 13 startsabove the screening drums 21 and passes or flows through the sleeveopenings of the screening drums 21, and then reaches and passes throughfluidized bed region 11 until it reaches the end 14.

[0035] In the screening drums 21, the fiber material that is not or forthe most part not separated reaches the inside surfaces of the sleevesfor the screening drums 21. The screening drums 21 rotate in a clockwiserotational direction 24. The mostly non-separated fiber material that isdeposited on the inner sleeve surfaces of the rotating screening drums21 is supplied to the separating drums 26. The separating drums 26rotate counter-clockwise in the direction 25 and are located offset withrespect to the center-axis of the screening drums 21. However, they canalso alternatively rotate in a clockwise direction, as well as in anyother conceivable variations of the rotational direction. The separatingdrums 26, which are needle rollers in the exemplary embodiment, pick upthe non-separated fibers, tear them apart, and accelerate them. Thefibers are tossed against the inner sleeve surface of the screeningdrums 21 until they have separated into individual fibers and havepassed through and/or can pass through the sleeve openings of thescreening drum 21. In an alternate embodiment, a drum with perforatedsheets or a rod-type grids can replace the screening drum 21.

[0036] The separated fibers are picked up by an air flow and are guidedand/or pulled through the sleeve openings in the screening drum 21. Theair flow moves the fibers downward toward the fluidized bed 11 and alongthe fiber flow 18. As soon as the fiber flow 18 arrives at the fluidizedbed 11, the flow 18 is deflected and guided along the curved fluidizedbed 11. As a result of the centrifugal forces acting upon the fibers,the fibers move toward the curved guide wall and flow to the suctionbelt conveyor (not shown in FIG. 1). The air flowing along above thefibers is removed at a wedge and/or separator 15 and is released throughexhaust pipe 16.

[0037] Optionally, individual fibers are picked up by an air flow 13coming from a nozzle lip 12 and are also supplied to the fluidized bedend 14, wherein several nozzle lips can also be provided.

[0038] Fiber groups that are not or not completely separated following asingle passage through one of the screening drums 21 reach therespectively parallel, second screening drum 21 via the circular flow23. The separating device shown in FIG. 1 at least in part correspondsto the device disclosed in International Patent Publication No. WO01/54873 A1 and/or U.S. Pat. No. 4,640,810 A, which are assigned toScanweb of Denmark and the United States and can be utilized in thepresent invention.

[0039] The fibers are essentially separated in a joint operation betweenthe screening drums 21, the separating drums 26, and the air flow 19, 23through the screening drums 21. In particular, essentially completelyseparated fibers are ensured by providing that only separated fibers areable to pass through the openings in the screening drums 21.

[0040] The fiber flows 18, generated by the transport air, move theseparated fibers in the direction of the fluidized bed end 14. Thethickness of the fiber flow 18 through the fluidized bed 11 iscontinuously reduced as a result of the centrifugal force. The flowdivider 15 is provided for separating the air from the fibers.

[0041] Turning to FIGS. 2-4, the non-separated fiber material 49 travelsvia the accumulation chute 44 to the metering device formed by the twofeed rollers 46, a metering channel arranged between the feed rollers46, and the spiked roller 76. The schematic representation in FIG. 3shows that the direction of the material feed-in 47 is downward and intoin the drawing plane. The non-separated fiber material 49 is separatedinside the separating device 10 (see FIG. 4). The separation of thefibers occurs through a joint operation of the separation rollers 26, anair flow 50, and openings in a grid or screen 77, which divides theseparating chamber 45 from the space that is assigned to the fluidizedbed 11. The air flow at the fluidized bed 11, generated by the air flowin the exhaust pipe 16, transports the separated fibers 27. As shown inFIG. 3, the direction of the air flow 17 in the exhaust pipe 16 isupward and out of the drawing plane, wherein the air flow 17 alsoremoves excess fibers.

[0042] The separated fibers 27 move along the fluidized bed 11 in thedirection toward the fluidized bed end 14 where a conveyor 32,particularly a suction belt 43, is arranged. A low pressure exists atthe conveyor 32 as a result of the air continuously being suctioned out,which is shown schematically by air flow 28. The low air flow 28 holdsin place the separated fibers 27 against the air-permeable suction belt43.

[0043] The suction belt 43 moves in the direction of the continuous rodmachine 9, which is to the left in FIG. 2. A fiber cake and/or fiberflow 29 is compiled on the suction belt and increases nearly linearly insize in the direction toward the continuous rod machine 9. The compiledfiber flow 29, which varies in thickness, is trimmed with a trimmingdevice 31 to reach a uniform size at the end of a compiling zone on thesuction belt conveyor. The trimming device 31 can be a mechanicaldevice, for example, trimming disks or plates, or a pneumatic trimmingdevice such as air nozzles. In a pneumatic trimming device, a nozzlethat discharges the air flow is arranged horizontally at the end of thefiber flow 29 and removes out a portion of the fiber flow 29, so thatexcess fibers 30 are removed. A circular or a flat nozzle can be used.

[0044] After the trimming operation, the fiber flow 29 is divided into atrimmed fiber rod 33 and an excess fiber rod 30. A nozzle can also beused to pick up and remove off all fibers below a trimming dimension.The excess fibers 30 are returned to the fiber preparation process andcan later be used to form another fiber rod.

[0045] The trimmed fiber rod 33 is held against the suction belt 43 andis moved in the direction of the continuous rod machine 9. At thispoint, the trimmed fiber rod 33 is a loose fiber nonwoven which iscompacted with the aid of a compacting belt 35. However, it is alsopossible to use a roller, for example, a press roll 55 as shown in FIG.5, in place of the compacting belt 35 or to use several belts, rollers,and/or pulleys. As shown in FIG. 3, the fiber cake is furthermore alsocompacted on the sides by compacting belts 48 which are angled towardsone another in the movement direction. The compacting belts 48 areoperated in an exemplary embodiment at the speed of the suction belt 43.The serrated or toothed shape of the compacting belts 48 creates zonesof varying density in the compacted fiber cake. The filter rod is lateron cut in the zones with the higher density or compaction. The higherfiber density in the filter end region ensures a more compactconsistency of the fibers in this sensitive zone and, additionally,makes it easier to process the filter rods.

[0046] The trimmed and compacted fiber rod 34 is transferred to thecontinuous rod machine 9. For transfer to the continuous rod machine 9,the compacted fiber rod 34 is lifted off the suction belt 43 and thefiber rod 34 is then deposited on a format belt 58 and/or on a wrappingmaterial web 42 on the format belt 58 of the continuous rod machine 9.(See FIG. 8) The format belt, which is not shown in the FIGS. 1-4, andcan be a standard format belt. The transfer is aided by a nozzle 36,which directs an air flow 37 from the top onto the compacted fiber rod34. A fiber filter rod 38 is formed in the continuous rod machine 9 bypulling a wrapping material web 42 from a bobbin 41 and wrapping thewrapping material web 42 around the fiber material 38. A certaininternal pressure builds up in the fiber filter rod 38 as a result ofvolume reduction and the shaping of the compacted fiber rod 34 into acircular and/or oval form during the wrapping with the wrapping materialweb 42 or, as shown in the following embodiments, before the wrappingwith the wrapping material web 42.

[0047] Bonding components that are contained in the fiber mixture aresurface heated and slightly melted in a curing device 39. For example,bi-component fibers can be used, the outer layers of which can be meltedso that a bond is created between the fibers. For this, reference ismade to German Patent Document DE 102 17 410.5 owned by the assignee ofthe present invention. A plurality of fibers suitable for providing thedesired filter characteristics can be used for the fiber materials,particularly cellulose acetate, cellulose, carbon fibers andmulti-component fibers, particularly bi-component fibers.

[0048] In another exemplary embodiment, different fiber types are mixedprior to the formation of the rod. It is furthermore possible to add atleast one additive, for example a bonding agent such as latex ortriacetin or a granulate material, such as activated carbon granulate,which is particularly effective for bonding components of cigarettes.

[0049] In yet another exemplary embodiment, the length of the fibers isshorter than the length of the filter and/or the filter element to beproduced. Consequentially, the fiber length in the exemplary embodimentshould be between 0.1 mm and 30 mm and, in particular, between 0.2 mmand 10 mm. With respect to the length, the filter to be produced can bea standard cigarette filter and/or a filter segment for multi-segmentfilters used for cigarettes. If the average fiber diameter additionallyis in the range of 10 to 40 μm, in particular 20 to 38 μm, moreparticularly between 30 and 35 μm, a very homogeneous filter can beproduced.

[0050] The curing device 39 can include one or more of the following: amicrowave heater, a laser heater, heating plates and sliding contacts.By heating the bonding components, for example in the outer layer of thebi-component fibers or latex material, the individual fibers in thecontinuous fiber rod will bond and melt together on the surface. Thecuring device 39 can also be used to dry bonding components which areadded in liquid form. During the cooling down of the continuous fiberrod, the slightly melted regions of the heated bonding components willharden again. The resulting grid imparts stability and hardness to thecontinuous fiber rod.

[0051] The cured fiber filter rod 38 is subsequently cut into individualfilter rod elements 40. However, the filter rod can also be curedfollowing the cutting into individual filter elements 40.

[0052] Referring to the embodiment of FIGS. 5-8 and in contrast to thecontinuous-rope machine 9 shown in FIGS. 2-4, the separated fibermaterial 27 is compiled from above onto the suction belt 43 in transportdirection 74. The separating device 10 of FIGS. 5-7 represents amodified embodiment of the separating device 10 in FIG. 1. Theseparating chamber 45 contains screening drums 21 that rotate in thedirection of the arrow 24. In a modified machine as compared to FIG. 1,however, the separating rollers 26, for example spiked feed rollers, arearranged in the center of the screening drums 21. As in the previousembodiment, the spiked feed rollers 26 function to tear apart andseparate the fiber material that has not yet been separated and/or thecohesive fiber groups into individual fibers, so that the separatedfibers can pass through the discharge openings in the screening drum 21and into the funnel 53. Owing to the respective air flows and the forceof gravity, the separated fibers 27 then reach the suction belt conveyor43, which in this embodiment has suction belt side walls 57. (See FIG.7)

[0053] A corresponding fiber nonwoven 29 is compiled on the suction belt43. Excess fiber material 30 is removed from above with the aid of atrimmer 31 from the remaining fiber rod 33. The trimmed continuous fiberrod 33 is compressed with a press roll 55, which simultaneouslyfunctions in the rod conveying direction as the rear reversing mechanismof the suction belt 43′. Shortly after the press roll 55, the compactedcontinuous fiber rod 34 is held from above by a suction belt 43′. Forthis, a low pressure field 54 is generated with an air flow 28. An airflow 37 then flows through the nozzle 36 onto the suction belt forremoving the rod from the suction belt 43′. The compacted continuousfiber rod 34 is removed from the suction belt 43′ with the air flow 37from nozzle 36 and is transferred to a format device 56. In the process,the compacted fiber rod 34 is deposited onto a wrapping material web 42,which is conveyed on a format belt. The remaining process stepscorrespond to those shown in FIGS. 2 to 4.

[0054] Referring to FIG. 8, which schematically shows a section of amachine in accordance with the present invention, the suction belt 43 isreversed around rollers 59. The gradually built-up fiber nonwoven 29becomes the trimmed continuous fiber rod 33 following the trimmingoperation. The trimming device is not shown in FIG. 8. In the compilingregion for fiber nonwoven 29 shown in FIG. 8, individual fibers 27 reachthe continuous fiber rod from below.

[0055] The continuous fiber rod 33 is subsequently deposited on awrapping material web 42 that is positioned on a format belt 58. Theformat belt 58 and the wrapping material web 42 are deflected withcorresponding rollers 59, 59′, respectively. In the region of a roller61, the fiber rod 33 is deposited onto the wrapping material web 42,which represents the start of the format device 56 at which the wrappingmaterial web 42 is wrapped around the continuous fiber rod 33.

[0056]FIG. 9 shows a view from above of the device shown in FIG. 8, andshows in particular side walls 57. The separating device is not shown inFIG. 9 for clarity. The side walls 57, which also adjoin the continuousfiber rod 29 and/or 33, are formed by suction belts 43 which, in turn,are reversed by reversing rollers 59″. In the illustrated embodiment,three suction belts are shown, which is useful if the fibers areespecially short and thin, so that the fiber material is correspondinglyheld against the suction belt and/or the suction belts.

[0057]FIG. 10 illustrates a device for transferring the fiber rod fromthe suction belt 43 to the format device 56 and, in particular, to thewrapping material web 42. The continuous fiber rod (not shown in FIG.10) is transported from the lower region of the suction belt 43, whichis reversed with the reversing roller 59, to a clearance space betweenthe opposite arranged belts 62 in direction 75.

[0058] The curved belts 62, which can be steel belts in an exemplaryembodiment, are reversed with the aid of curved rollers 63. A circularhollow space is thus created between two opposite arranged belts 62. Thecontinuous fiber rod passes through this hollow space with circularcross section and is deposited on the wrapping material web 42. Thefiber rod 34 (see FIGS. 2 and 5) can be pre-formed and, if necessary,additionally compacted with the transfer device. The suction belt sidewalls 57 for this embodiment are designed as solid side walls.

[0059]FIG. 11 shows a section of a continuous rod machine 9, wherein inaccordance with the invention, fiber flow 29, consisting of fibers 27supplied from above through a funnel 53 and compiled on the suction belt43 is conveyed to the operating range of a hugger belt 64, which isreversed around rollers 65. The respectively compacted fiber rod entersa nozzle 66 and is conveyed further with an air flow 67 to the wrappingmaterial web 42 which rests on the format belt 58. The fiber rod 38 issubsequently wrapped with the wrapping material web 42 to form thecontinuous fiber filter rod 38.

[0060] An alternate embodiment for transporting the fiber rod 33 to theformat belt 58 is shown in FIG. 12. The fiber rod 33 is conveyed by thesuction belt 43 to the operating range of a nozzle 68, which blowscompressed air 69 onto the fiber rod 33 in the region of the reversingroller 65, thus separating the continuous fiber rod 33 from the suctionbelt 43. The angle for the nozzle 68 and/or the compressed air 69 blownonto the fiber rod 33 can be adjusted. After the fiber rod 33 isseparated from the suction belt 43, the fiber rod 33 travels to the ringnozzle 70. The air 67 flowing through the nozzle slit 71 can performvarious functions, depending on the nozzle design. However, the functionin the exemplary embodiment involves separating the fiber rod 33 fromthe suction belt 43, which runs around the reversing roller 65 and canalso be designed as press roll 55, with the aid of the low pressureexisting in the nozzle feed channel of nozzle 70. In addition, thecompressed air 67 blown against the fiber rod at specific angles canconvey the fiber rod to a first format-forming hollow cone 72, and.According to a modification, the compressed air 67 can dissolve the rodinto individual fibers and/or fiber groups and thus convey theindividual fibers and/or fiber groups into the first format-forminghollow cone 72, and subsequently into a second format-forming hollowcone 73. The format belt 58 with the wrapping material web 42 positionedthereon passes underneath the second format-forming hollow cone 73. Thesecond hollow cone 73 has a smaller taper than the first hollow cone 72.The first format-forming hollow cone 72 contains venting bores whichensure the discharge of the nozzle air 69 and 67.

[0061] In another exemplary embodiment in which the fiber rod 33 istransferred as continuous fiber rod, the fiber rod is shaped from thetop by the format-forming hollow cones 72 and 73 and from the bottomwith the format belt 58 that passes through the format device. Thecomplete transfer of the fiber rope 33 to the format belt and/or thewrapping material web 42 occurs below the hollow cone 73. In the secondvariant in which individual fibers and fiber groups are pressed into theformat-forming hollow cone with the aid of nozzle air 69, a backup ofthe individual fibers and fiber groups occurs because of the taper inthe hollow cone, so that a new fiber rod forms. This rod is formedcompletely in the second hollow cone 73 and is transferred at the end ofthe second hollow cone 73 to the format belt and/or the wrappingmaterial web 42. The wrapping material web 42 is then wrapped around therod to form the continuous fiber filter rod 38.

[0062] In contrast to cigarette rod production, the difficulty with thecontinuous filter rod production, as in the present invention, is thatfilter materials having fine fibers with or without additives such asactivated carbon granulate or powder must be formed into homogeneousfilter rods. The various elements and/or devices must accordingly beconfigured so that the materials used are transported, held or processedin an optimum manner.

[0063] The fiber materials can be cellulose fibers, fibers of athermoplastic strength, flax fibers, hemp fibers, linseed fibers,sheep's wool fibers, cotton fibers or multi-component fibers, inparticular bi-component fibers having a length that is shorter than thatof the filter to be produced and a thickness, for example, in the rangeof 25 to 30 μm. For example, cellulose fibers of the type “stora fluffEF untreated” by the company Stora Enso Pulp AB can be used, which havean average cross section of 30 μm and a length of between 0.4 and 7.2mm. For the synthetic fibers such as the bi-component fiber, it ispossible to use fibers with a length of 6 mm of the type Trevira 255 3.0dtex HM by the company Trevira GmbH. These fibers have a diameter of 25μm. Cellulose acetate fibers, polypropylene fibers, polyethylene fibersand polyethylene terephthalat fibers can also be used for the syntheticfibers. Materials that influence the taste and/or smoke can also be usedas additives, such as activated carbon granulate or flavoring agents, aswell as bonding agents that make the fibers stick together.

[0064] The invention has been described in detail with respect toexemplary embodiments, and it will now be apparent from the foregoing tothose skilled in the art, that changes and modifications may be madewithout departing from the invention, therefore, as defined in theappended claims, is intended to cover all such changes and modificationsthat will fall within the true spirit of the invention.

What is claimed is:
 1. A method for producing a continuous filter rod,comprising: transporting at least one type of finite, essentiallycompletely separated fibers with transport air to a conveyor; forming afiber nonwoven on one surface of the conveyor to result in the fibers atleast partially contacting one another; depositing the fiber nonwovenonto a wrapping material web; and wrapping the fiber nonwoven with thewrapping material web.
 2. The method of claim 1, wherein the wrappingstep includes compacting the fiber nonwoven.
 3. The method of claim 1,wherein during the wrapping step or following the wrapping step, themethod further comprises applying energy to the fiber nonwoven to createa bond at points of contacts between the fibers.
 4. The method of theclaim 1, wherein the continuous filter rod is subsequently cut into atleast one of filters and filter elements, and wherein the fibers have alength shorter than the filters and the filter elements.
 5. The methodof claim 4, wherein the at least one type of fibers contains fibers withan average diameter between about 10 μm and about 40 μm.
 6. The methodof claim 4, wherein the at least one type of fibers contains fibers withan average diameter between about 20 μm and about 38 μm.
 7. The methodof claim 1, further comprising adding additives to the fibers.
 8. Themethod of the claim 1, further comprising compacting the fiber nonwovenprior to the depositing step.
 9. The method of claim 7, wherein theconveyor conveys the fiber nonwoven in a movement direction, and whereinthe compacting step includes compacting the fiber nonwoven in at leasttwo directions that are perpendicular to the movement direction.
 10. Themethod of claim 1, wherein the depositing step includes mechanicallyremoving the fiber nonwoven from the conveyor.
 11. The method of claim10, wherein the removing step includes utilizing compressed air.
 12. Themethod of claim 1, further comprising shaping the fiber nonwoven priorto the depositing step.
 13. The method of claim 12, wherein the conveyorconveys the fiber nonwoven in a movement direction, and wherein in theforming step includes forming at least a semicircle crosswise to themovement direction.
 14. The method of claim 13, wherein the forming stepincludes forming a full circle.
 15. The method of claim 1, wherein thedepositing step occurs at least in part before the forming step.
 16. Afilter element cut from the continuous filter rod produced according tothe method of claim
 1. 17. A machine for producing a continuous filterrod, comprising: a conveyor; a fiber compiling device that transportsseparated fiber materials with transport air to the conveyor to form afiber nonwoven; a format device downstream of the compiling device forwrapping a material web around the fiber nonwoven; and a transferringdevice for transferring the fiber nonwoven from the conveyor to theformat device.
 18. The machine of claim 17, further comprising at leastone compacting device at the conveyor.
 19. The machine of claim 18,wherein at least a section of the conveyor forms at least a part of thecompacting device.
 20. The machine of claim 17, wherein the conveyorcomprises at least one suction belt.
 21. The machine of claim 20,wherein the conveyor comprises at least three suction belts.
 22. Themachine of claim 20, further comprising means for removing the fibernonwoven from the suction belt with compressed air.
 23. The machine ofclaim 17, wherein the transferring device comprises a transport belt.24. The machine of claim 23, wherein the transport belt has a concavedesign.
 25. The machine of claim 23, wherein the transferring devicecomprises two transport belts.
 26. The machine of claim 17, wherein thetransferring device comprises a nozzle through which the fiber nonwovenis transported.
 27. The machine of claim 26, wherein the nozzle shapesthe fiber nonwoven into at least one of a round and oval form.